Investment interest calculator
Enter the amount, the rate, the length and, if you like, a regular deposit. The chosen rhythm is used for both interest and deposits.
Result
5,467.68Interest earned
- Final amount
- 27,467.68
- Total paid in (start included)
- 22,000.00
- Real rate over a year (compounding effect)
- 3.04%
Year by year
Detailed table
| Year | Paid in | Interest | Total |
|---|---|---|---|
| 1 | 11,200.00 | 320.80 | 11,520.80 |
| 2 | 12,400.00 | 687.85 | 13,087.85 |
| 3 | 13,600.00 | 1,102.57 | 14,702.57 |
| 4 | 14,800.00 | 1,566.40 | 16,366.40 |
| 5 | 16,000.00 | 2,080.84 | 18,080.84 |
| 6 | 17,200.00 | 2,647.42 | 19,847.42 |
| 7 | 18,400.00 | 3,267.74 | 21,667.74 |
| 8 | 19,600.00 | 3,943.42 | 23,543.42 |
| 9 | 20,800.00 | 4,676.16 | 25,476.16 |
| 10 | 22,000.00 | 5,467.68 | 27,467.68 |
How it is calculated
- Rate per period i = yearly rate ÷ periods per year.
- Each period: balance × (1 + i), then the deposit is added (or before, for deposits at the start).
- Interest = final amount − everything paid in.
- Real rate over a year = (1 + i)^periods − 1.
Example
10,000 at 3% for 10 years, plus 100 at the end of each month: 5,467.68 of interest, for a final amount of 27,467.68.
Good to know
- Fixed rate for the whole length. No tax or fees.
- Interest is added at the same rhythm as the deposits.
- An estimate: your bank’s rules may differ (value dates, day counts…).
Frequently asked questions
What is this tool used for?
Enter the amount, the rate, the length and, if you like, a regular deposit. The chosen rhythm is used for both interest and deposits.
How is the result calculated?
Rate per period i = yearly rate ÷ periods per year.
What should I check before using the result?
Fixed rate for the whole length. No tax or fees.